Heap address disclosure via uninitialized event fields
Published Nov 3, 2025 · Updated Nov 3, 2025
Uninitialized memory exposure in NetSurf 3.11 and earlier allows remote attackers to read partial heap addresses through JavaScript. The _dom_event_initialise function leaves several dom_event fields unset, allowing event.eventPhase to return stale heap contents. When attacker-controlled JavaScript runs in the browser, it can expose the lower four bytes of a heap address as a partial information-leak primitive.
Summary
What happened
Uninitialized memory exposure in NetSurf 3.11 and earlier allows remote attackers to read partial heap addresses through JavaScript. The _dom_event_initialise function leaves several dom_event fields unset, allowing event.eventPhase to return stale heap contents. When attacker-controlled JavaScript runs in the browser, it can expose the lower four bytes of a heap address as a partial information-leak primitive.
The record
- CVE
- CVE-2025-45663
- Published
- Nov 3, 2025
- Updated
- Nov 3, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-244
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 3, 2025CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- CVE-2025-45663 poc.htmlproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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